Sub-frame connectors

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70aarcuda said:
What is the purpose of sub frame connectors?...to tie the sub frames together...Does it matter if the sub frame connectors are off a few degrees or not level...will the sub frames still be tied together...???



Too much thinking...Just do it....
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Point is, if the body is torqued out of alignment by not being supported correctly, then you weld the sub frames together, you have locked in the twist.

No, these questions are not over thinking but some over thinking is going on here.

Just don't have your car jacked all weird, take look at your panel fit and things will be fine.
 
Mine were welded in when it was just a shell. Doors open just fine whether the car is on jack stands or the wheels. I would think that if your ride was together, motor in it and what not and you were to put them in you might have some troubles depending on how the car were supported.

I have had a few folks that the inner fenders provide support. While they might provide some I invite folks to try this. Put your car up on jackstands with the fenders on it. Unbolt the fenders and front bumper, leaving the brackets on. Attach a chain to the bumper brackets and then lift the front of the car with an engine hoist. If your ride is like ours was, and our car was a California car with 0 rust in the front of it, it will flex. Ours flexed enough to pop out all the seam sealer. Front end of frame went up about 3.5" before any movement occurred at the jack stand, which was on the frame rail a bit behind the firewall. What this proves to me is that you are relying on the front fenders to provide support. And sheet metal will fatigue after a while....
These cars are flexy fliers. Subframe connectors do help but they are on the wrong plane to stop the front of the car from drooping when one accelerates. What is really needed, in my OPINION, is snout bars (if you have a cage) or j-bars similar to what Dillinger WAS offering. This picture is from the Magnumforce web site showing how they can be done if you do not have a cage.


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This is a picture of a car that Hemi Denny posted

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Triangles, along with boxing, are what creates strength. While subframe connectors help eliminate the flex between the front and rear frame sections they are on the same plane as the frames. True support comes from a well built cage. Not saying to put a cage in your car but subframe connectors are only a part of the equation. No doubt there is going to some folks that are going to try to argue with me over this. Go right ahead... But again, go and take the fenders off of your car and try what I mentioned above. Facts are pretty tough to argue over. Go and look at how a properly built off road cage is built and you will see triangles damn near everywhere.

People will often say motor/mid plates are nothing but trouble thanks to the vibrations they put into the car. But a one piece motor plate coupled with a one piece mid plate are very good at providing stability between the frame rails...provided that they have a pair of fasteners at each end. Again, argue all you want but some of this stuff is fairly simple engineering.....
 
So, armed with the info in this thread, I think this will be the plan:
*Double-check level of car and jacks
*Get a set of Mancini bolt/weld-ons and bolt 'em up
*Finish the underside of the car
*Have the subs welded on at a later date
Should work, no?:-k
 
I weld them on the Torsion bar crossmember and then jack them up against the pan where it starts to lift my car off the stands. Takes that sag out of the car. Funny the doors closed better. I test the door open/close as I do it. Why would you want to lock in non engineered sag?

If the doors aren't on, you get to align them anyways along with your fenders. It doesn't matter.

So... with the crummy tolerances to start with that these cars were built, it's a lot of overthinking.

Too much thinking...Just do it....
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Get the car level and go at it.
 
crackedback said:
I weld them on the Torsion bar crossmember and then jack them up against the pan where it starts to lift my car off the stands. Takes that sag out of the car. Funny the doors closed better. I test the door open/close as I do it. Why would you want to lock in non engineered sag?

If the doors aren't on, you get to align them anyways along with your fenders. It doesn't matter.

So... with the crummy tolerances to start with that these cars were built, it's a lot of overthinking.



Get the car level and go at it.
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bottle jack works wonders.....dam cars are over 40 yrs old...sagging just like an 45 yr old woman...
 
a buddy of mine builds older mopars to race circle track as a hobby, his dad used to race ARCA series in the late 60s and early 70s, he has a lot of information on this subject as his dad used to be in touch with Chryslers former chassis engineer on mopars stock car program. A man by the name of WWWLarry Rathgeb.

i asked him about the subframe connectors for my cuda. he said level the car body shell on 4 jackstands. i asked him how do i know its level the concrete floor could be slightly off. he said you shim the jackstands where they meet the body with sheetmetal shims as necessary to make it level. said to use a couple spirit levels. you know the bubble levels carpenters use.

build andand fit your conectors first, then when your ready to install them you will need to jack and level the car before welding them in.

set a spirit level on each rocker panel in each door opening where your door sill plates screw down, same location both sides. set one across the flat upper shock mounting panel in the trunk, and one across the radiator upper support inner flange, this is where its flattest here. if radiator is in car just loosen the bolts and lay it back.

then its jack and shim until all 4 levels are centered. then fit your subframe connectors in, clamp, and tack weld in a few spots. recheck your levels to make sure they are still level, then zap it all together. these cars arent built perfect so dont expect the bubble levels to all be dead on center but they should be really close.

as another poster said you can align body panels to suit when it goes back together. these cars werent robot welded and therefore arent perfect. but are close enough to work. from his experience welding the connectors into an empty leveled shell is preferred over preloading the body.

just my .02 and some ideas
matt
 
crackedback said:
I weld them on the Torsion bar crossmember and then jack them up against the pan where it starts to lift my car off the stands. Takes that sag out of the car. Funny the doors closed better. I test the door open/close as I do it. Why would you want to lock in non engineered sag?
...
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That's pretty much how I installed mine aswell.
Drove the car on my 4-post lift, positioned the connectors under the car, welded the front to the crossmember with a few welds. Then put a transmission jack under the rear of the connectors and pushed them up very tight against the floorboards and over the rear framerails and welded them in.

Doors opened a little different but I find it more assuring some of the body-sag has been taken out of the car now.
Doors hinges are mounted with bolts so you can adjust them. That why they are there for.
 
Here is my 1962 Valiant with home made sub frame connectors in 3mm steel.
 

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do they have to be welded continuously along floor pan like that?
 
Ofcourse it's better for the car's rigidity to weld the floor boards to the subframe connectors.

Although 3mm thick steel bend into a U-frame is a bit overkill and mostly just adds weight.
 
that's what I thought. I just put in the US Cartool connectors. solid at the frame then healthy tacks every 4-6" along length.
 
BigBlockMopar said:
Ofcourse it's better for the car's rigidity to weld the floor boards to the subframe connectors.

Although 3mm thick steel bend into a U-frame is a bit overkill and mostly just adds weight.
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Well, I´m a new beginner on this, and then its easy to overkill :glasses7:
I´m Learning as long as I live :D
 
Cut the crap, just weld in some 2x3 rectangle tube with some fish plates at the front end, seal the tube off in the rear, and call it a day. No need for this 'the sheet metal will make it or break it" bullhockey.

Your trying to tell this guy, that if you take the roll out of the paper towels, and glue a piece of that paper to either side of it, to the roll it will be stronger? OK.

Do you also believe that the 'wings' on maxi-pads make them fly? C'mon dude.

http://www.forabodiesonly.com/mopar/showthread.php?t=209632
 
I like the approach in post # 36 anyone care to add to that, good or bad.I throught of putting jack stands under the the rear supporting the weight, and putting the front tires on wheel ramps,but my floor is not level hence the car would not be level ? i need help i don't want to screw this up.:eek:ops:
 
BrianT said:
I can give you an example of why we welded mine in on a drive on rack. When we lifted the car on a frame rack, the gap at the top of the fender would open up and the doors wouldn't open. There was nothing wrong with my sub-frame, no rust or rot, it was just a 40+ year old unibody car. Once we welded the connectors in place, I can lift it up and these problems disappeared.

If you can put your car up on four jack stands and everything still lines up okay and your doors work fine, then I say go for it. If they don't, I would put the jacks under the rear axle tubes, and then under the K frame to support the weight of the engine and front sub frame. This would basically be the same as a drive on lift.

The same on a rotisserie, if everything is lining up, weld them in.
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Had mine installed on a drive on rack which I've heard is the best way. I made my own connectors then had the mufflers shop weld them in.
 
PoisionDart74 - Post # 46 says it all. To sum it as I would say , Don't overanalyze....just Do It ! I myself have been looking into this same subject and that is what I am going to do. You can drive yourself crazy like I did on this subject. You can take all the good info that these great people here have given you and I think you and I will be able to do a great Job ! I am just going to jump right in and hope for the best. Good luck to you ! MERRY CHRISTMAS Tim (Dad)
:thumrigh:
 
one mile said:
PoisionDart74 - Post # 46 says it all. To sum it as I would say , Don't overanalyze....just Do It ! I myself have been looking into this same subject and that is what I am going to do. You can drive yourself crazy like I did on this subject. You can take all the good info that these great people here have given you and I think you and I will be able to do a great Job ! I am just going to jump right in and hope for the best. Good luck to you ! MERRY CHRISTMAS Tim (Dad)
:thumrigh:
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Thankssssssssssssssssssss,Merry Xmass to you.
 
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